Dejan Lovren has completed his move from Southampton to Liverpool for a fee of 20 million pounds.

Croatia international Lovren has signed a four-year contract after passing a medical on Merseyside on Saturday. The 25-year-old has become the Reds' fifth signing of the summer, and their third from Southampton.

Midfielder Adam Lallana -- who is currently out of action with a knee injury suffered during pre-season training -- and striker Rickie Lambert have moved to Anfield from the south coast, while Germany Under-21 international Emre Can has arrived from Bayer Leverkusen and Serbian winger Lazar Markovic has come in from Benfica.

Lovren told Liverpool's website: "It's a dream come true. I'm happy and glad to be here. I'm proud and can't wait to start. I know we have millions and millions of supporters -- Liverpool is more than a club.

"After I played at Anfield last season, I said to myself: 'One day I hope I'll be able to play here for Liverpool.' The fans will know from the first minute that I'm a player that will give 100 percent on the pitch."

The Croatia centre-back has been manager Brendan Rodgers' top defensive target this summer. The boss had been looking to strengthen a defence that conceded 50 Premier League goals despite finishing in second place last season, and feels that Lovren -- who played in all three of Croatia's matches at the recent World Cup in Brazil -- has the leadership qualities to make Liverpool more solid at the back.

"This is a very important signing for us and I'm delighted it's completed so Dejan can join up with us on our US tour," Rodgers told Liverpoolfc.com. "He is a commanding and powerful presence and clearly has leadership skills, which is important; he fits the profile of player we are looking for.

"He is still relatively young, so his peak years are ahead of him and I believe he will improve and progress even further with us. I'm looking forward to him arriving and working with us as we continue our preparations for the new season."

Lovren has happy memories of that visit to Anfield last September -- he scored the only goal as Southampton secured a 1-0 Premier League win. The defender, who played in all three of Croatia's matches at the recent World Cup, moved to St Mary's Stadium from Lyon in June 2013 for 8.5 million pounds.

His signing has been confirmed hours after Liverpool pulled out of a deal to sign QPR striker Loic Remy because of concerns over his medical.

A statement on the Southampton website read: "Southampton Football Club can confirm that it has reached an agreement with Liverpool over the transfer of Dejan Lovren. The defender, who joined Saints last summer on a four-year contract, departs for a significant fee after negotiations with the Anfield club."